Blok C.,Wageningen UR Greenhouse Horticulture |
De Boer-Tersteeg P.,Wageningen UR Greenhouse Horticulture |
Van Der Maas A.A.,Wageningen UR Greenhouse Horticulture |
Khodabaks R.,Wageningen UR Greenhouse Horticulture |
Acta Horticulturae | Year: 2014
Recycling of the nutrient solution during cultivation of greenhouse crops reduces the total input of water and fertilizers and decreases emission of nutrients to the environment. However growers fear accumulation of harmful substances in the drain water. For this reason drain water in practice is regularly discharged into the environment. In this study drain water from a commercial rose grower in The Netherlands was tested with a phytotoxicity test (Phytotoxkit) during a period of one year. The Phytotoxkit was used to assess growth response of drain water without disinfection; drain water disinfected with UV; drain water disinfected with UV and peroxide. In this phytotoxicity test, garden cress (Lepidium sativum) and mustard (Sinapis alba) are grown in a Phytotoxkit container on a filter paper moistened with the drain water under analysis. After incubation for three days in a climate-controlled cabinet, root length is measured. The Phytotoxkit showed growth decrease caused by untreated drain water disappeared when using a UV disinfection of 100 MJ.cm-2 or UV disinfection of 100 MJ.cm-2 combined with 10-25 ppm peroxide. Untreated drain water caused growth responses of -20% root length in only 3 out of 10 sample moments. Control of drain water with the Phytotoxkit provides the grower information about the presence of phytotoxic substances in the drain water and the effectiveness of treatments. The Phytotoxkit thus can prevent unnecessary discharge of drain water to the environment.
Raaphorst M.G.M.,Wageningen UR Greenhouse Horticulture |
Van Der Maas A.A.,Wageningen UR Greenhouse Horticulture |
Blok C.,Wageningen UR Greenhouse Horticulture |
Beerling E.A.M.,Wageningen UR Greenhouse Horticulture |
Acta Horticulturae | Year: 2014
The EU Water Framework Directive demands a sound ecological and chemical quality for ground and surface waters. The Dutch greenhouse industry is on track towards a sustainable water management with the aim of a zero-emission of nutrients and plant protection products (PPP) in the year 2027. Growth inhibition, especially in rose cultivation, is a major reason for discharge of drain solution in soilless growing systems. Previous research on laboratory scale has shown the benefits of advanced oxidation process (here H 2O2 + UV)) as a water treatment method to eliminate growth inhibiting factors. The next step is implementation in practice. Two paths have been explored (i) an endurance test on a cut rose nursery and (ii) monitoring the quantity of water flows in 12 nurseries with gerberas, roses, green peppers, cucumber or tomatoes, which were applying a combination of H2O 2 and UV as AOP. In the cut rose experiment, no differences in crop yield were found between the treatments, despite of growth inhibition in the bioassay. The results from this trial led us to make the conclusion that for a period longer than a year, not more than a minimal discharge of drain water is necessary to avoid growth inhibition in a rose crop. Participation of the growers in the monitoring group using AOP led to a greater awareness of their water use and the emission flows on the nurseries, an incentive to learn from each other and willingness to try new things out. The quantities of water flows in the different nurseries have been compared. The average drain water discharge in 2011 has decreased with 45% compared to 2010. The calculated nitrogen emission was 157 and 86 kg N.ha-1, respectively for 2010 and 2011. These discharge figures were compared to model calculations, which calculate nursery-specific discharge based on sodium accumulation only. The model predicted an average discharge of 104 m3 in 2010 and 88 m3 in 2011. Effective doses of AOP for the prevention of growth inhibition are 15-25 mg.l-1 H2O2 and 100-250 mJ.cm -2 UV. With the use of AOP, the growers were more confident in the quality of the irrigation water. At one nursery, AOP was the ultimate solution for the serious growth inhibition problems.
According to the United Nations, the earth will house an estimated 9.7 billion people by 2050. Consequently, more food will need to be produced over the next four decades than has been produced over the last 10,000 years. And with more than 99.7 percent of global food coming from land, and most of the arable land already accounted for, increasing yields per surface area is essential. One crop production solution creating opportunities for investors, entrepreneurs and multinational companies is vertical farming, aka plant factories. Although nomenclature varies, the concept involves growing crops on urban rooftops or in high rises or other controlled, indoor environments, which build vertically in stacks as opposed to spreading horizontally. Vertical farming uses fewer water and land resources while limiting pollution and the impacts of oft-volatile Mother Nature. It also moves production closer to urban consumers, which reduces transport distances, minimizing waste and extending shelf lives. These soil-less systems employ hydroponics (where roots are marinated in nutrient solutions) or aeroponics (roots are sprayed with nutrients). LED lights and metal reflectors magnify illumination and advanced HVAC systems maximize production. Recently, dozens of vertical farming companies displayed their technologies at the four-day Taipei International Plant Factory and Greenhouse Horticulture Product Exhibition. A range of enterprises participated, from startups to global conglomerates: plant factory design and engineering companies, irrigation and artificial mist suppliers, LED manufacturers and sensor technology developers. Lu Wen-Yuan, a Taiwanese representative for Japanese-based Toyobo Engineering, talked about the ability to keep food safe in plant factories and how year-round growing seasons increase per land area output manifold. He said, “because it is a closed system, daily production is stable and not reduced by the weather — such as typhoons, rain and wind.” Lu also highlighted the reduced costs and environmental impact from converting unused buildings into vertical farms (as opposed to constructing new structures). Recognizing indoor farming’s potential, Taiwan electronics manufacturer, Advanced Connectek, started a plant engineering unit, ACON Pure. Within Taiwan, ACON Pure markets factory-grown crops. Globally, the company assists third-parties to construct controlled-system farms by designing facilities, transferring technology and providing training and management. Senior Director Sandy Wu extolled the benefits of vertical farming — no insecticides or herbicides, a 90 percent reduction in water usage relative to traditional farming and an even greater cutback in mineral nutrients. Similarly, Priva, which has approximately 500 employees operating in more than 100 countries, designs and constructs sustainable vertical farms that enable agricultural producers to control interior temperatures, irrigation, humidity, CO2 concentration and light. Priva’s Beijing-based General Manager, Julia Charnaya, said, “With droughts and the climate changing, production is switching from growing in open fields to closed operations in greenhouses or plant factories.” In Holland, Priva partnered with technology company Philips on urban farming research facilities. Philips’s 75-person horticulture LED division customizes lighting solutions for closed agricultural systems. Gus van der Feltz, Global Director of City Farming at Philips, said, “There are opportunities all around the world, particularly where people care about their food and have capital to invest…like with any new technology, we are looking at early adopters.” Given favorable economics, most vertical farming plants are lettuce varieties (e.g., coral, leaf, curly, wave, antler, sweet romaine), herbs (e.g., coriander, mint, basil), and cruciferous vegetables (e.g., broccoli, cabbage, bok choy, sprouts). Some plant factories raise strawberries, tomatoes, mushrooms and peppers. And as the industry develops, cropping possibilities widen. Functional and medicinal crops are also grown in factories. According to Wu, many Japanese hospitals have on-site plant factories producing specific crops for patients. For example, hospitals are experimenting with low-potassium spinach for patients with kidney issues. Others are experimenting with ways to lower food nitrate levels. Wu said, “In the future, we can distinguish products by individual medical needs. By controlling the quality of the nutrient solution, we control the quality of plant nutrients.” Van der Feltz said, “We can stimulate development of desirable compounds in fruit and create high-quality produce in vertical farms.” Startups are also capitalizing on industry opportunities. Taipei-based LED lighting company, Asensetek, was founded in 2013 and has 30 employees today. Although indoor farming only represents a fraction of their revenue, marketing representative Vincent Tsai said, “Business opportunities are expanding.” To attract agricultural clients, Asensetek developed a spectrometer that links with smart devices and enables growers to remotely monitor and analyze light wavelengths and intensities. Although many product suppliers target large-scale vertical farms, others are retail-focused. After three years of research and development, the five-person team at Taiwan-based Fresh Intake is marketing its mini-garden cabinet to households, cafeterias and restaurants. The 3′ x 6′ cabinet is an enclosed system that enables year-round growing of crops, which can be immediately eaten after harvesting. One criticism of indoor farming is the increased electricity usage, but supporters view the advantages as outweighing the negative externalities. Addressing the issue, van der Feltz said, “It’s a fair point on the light when not using the sun, but we think we can make the value chain more efficient and shorter.” To lessen the environmental impact from lighting, heating and cooling, many vertical farms use renewable energy. Fresh Intake’s engineer, Chia-Yu Yen, also acknowledged the trade-off, and said, “Hydroponics uses few nutrients, but if we plant crops in the earth it uses a lot of nutrients. This is a waste of the earth’s ground. Hydroponics also uses a lot less water.” He continued, “The planet has more and more people and hydroponic output is extremely high. I believe hydroponics will become more widespread as people learn about its benefits.” Yen also highlighted the value in growing crops in the markets in which they are consumed. He said, “Lettuce in Taiwan is imported. If we use hydroponics we don’t have to import it and it is less expensive and the quality is better.” Beyond Taiwan and the Netherlands, research and commercial vertical farms exist in the U.S., Canada, the U.K., Sweden, the Middle East, Japan, South Korea, China and Singapore. In the future, vertical farming may be further explored in land-scarce (e.g., China, India, Korea), water-scarce (e.g., California, the Middle East), non-temperate (e.g., Alaska, Scandinavia) and other markets where producers are trying to limit environmental influences. “Vertical farming has lots of potential and is a new and emerging market,” Priva’s Charnaya said. “And with land becoming more scarce and more expensive, it is probably the future.”
The interior climate of many buildings is poor. This is also the case for offices, schools, hospitals, and other public and semi-public buildings. Small-scale research suggests that plants can make a significant contribution to the resolution of problems in interior climates. A group of research institutes, social organisations and companies is now set to perform large-scale research into this. Companies and care institutes wishing to participate can register. Plants add moisture to the air, can help purify the air of undesired substances and also create a pleasant environment. All these factors can also deliver cost savings, both from a technical perspective (reduced need for artificial climate control, energy savings, etc.) and from the perspective of the improved performance of the users of the building (for instance expressed in lower rates of sickness absenteeism). So why has there not yet been a large-scale introduction of plants in buildings? "Because there are as yet insufficient concrete figures on the matter and insufficient innovative and usable green solutions," explains project leader Annemieke Smit of Alterra. "There is a lack of awareness and hard evidence of the economic effects achieved through cost savings on the technical side and improvements for the user. In other words, no cost-benefit analysis has been carried out on which companies and institutions can base their policies and actions if they want to make the interiors of their premises greener." The research should lead to an improved use of greenery in buildings for a more sustainable set-up and a healthier living and working climate. The research that has been performed so far has generally been of too small a scale, too fragmented or carried out under laboratory conditions. A new innovation project will not only look at what plants physically contribute to the air quality in buildings, but also the influence of this on the health and well-being of the people working or living there. In this way, the researchers want to examine the actual effects of the large-scale use of plants on the interior climate. As part of this, attention will also be devoted to the costs and benefits of this. For instance, can savings be made with regard to the traditional, energy-wasting air treatment systems? Can plants reduce sickness absenteeism, or boost people's powers of concentration and therefore also their productivity? The study forms part of De Groene Agenda (The Green Agenda), an overarching programme for a healthy living and working environment, thanks to a grant from the Horticulture & Propagation Materials top sector, and will be carried out by a large consortium of institutions and companies, including Alterra Wageningen UR, Fytagoras, Wageningen University, the IVN, the Dutch Green Building Council, the iVerde foundation, FloraHolland, Noviflora, Donkergroen and Priva. "We are now just looking for companies and health-care institutions that would like to participate; in other words, practical locations at which we can carry out the research," says Annemieke Smit. "Interested parties can contact us." Explore further: Imaginative ideas for a 'greenlight district' in Amsterdam
Pallubinsky H.,Maastricht University |
Schellen L.,Maastricht University |
Schellen L.,AVANS University of Applied Sciences |
Rieswijk T.A.,Priva |
And 3 more authors.
Energy and Buildings | Year: 2016
Public and commercial buildings tend to overheat. Recent studies indicate individual comfort systems based on local climatization can improve occupant satisfaction and simultaneously decrease the energy load of buildings. This study evaluated the effect of local cooling in both women and men on indicators of occupant satisfaction: thermal sensation, thermal comfort and skin temperatures. All measurements were conducted in a climate chamber (Priva, the Netherlands) with an ambient temperature of 32.3 ± 0.3 °C (mean ± SD). In total, 16 healthy young men and women were exposed to different local cooling conditions for 45 min: face cooling, back cooling, underarm cooling, foot sole cooling and 30 min of combined face-underarm cooling. The cooling conditions were separated by 30 min of 'no cooling'. Thermal sensation and thermal comfort were evaluated with VAS-scales. Skin temperatures (26 sites) were measured using wireless temperature sensors. 'Face cooling' and combined 'face-underarm cooling' significantly improved thermal sensation and comfort compared with 'no cooling' for both women and men. Women had significantly higher skin temperatures compared with men. Local cooling of the face alone and face and underarms combined are effective ways to improve thermal sensation and thermal comfort in a warm thermal environment. © 2015 Elsevier B.V. All rights reserved.